Sen. Bill Nelson, D-Fla., requested that the Environmental Protection Agency weigh in on an unauthorized oil drilling incident close to the Florida Everglades.

The Florida Department of Environmental Protection already has intervened in the situation, which happened south of Lake Trafford in Collier County. According to the state, Texas-based Dan A. Hughes Co. conducted unauthorized activities at its Collier County site, moving ahead with a new extraction procedure even though the state had requested it wait.

The activities took place in December 2013. The company proposed what the state called an “enhanced extraction procedure that had not previously been used in Florida,” one that would involve injecting a dissolving solution at sufficient pressure to help enhance oil production.

When the state caught the company engaged in the activities it had yet to authorize, it said it took immediate action and assessed the maximum civil penalties it could. In a consent order between the state and the company, the Department of Environmental Protection required the company to pay $25,000 and to hire an independent expert to conduct ongoing groundwater monitoring of the area, checking for any damage to the environment or risks to the public.

Nelson, in his letter to the EPA, said the process used was akin to fracking, the controversial procedure in which high-pressure water and chemicals are pumped underground to break up shale rock and release the oil and natural gas inside.

David Blackmon, a spokesman for Dan. A Hughes Co., said in a statement that the procedure used was not fracking – and indeed was similar to what are known as “acid stimulations” that have been commonly used in Florida for over 50 years.

“Compliance with the law is a core operating principle for Dan A. Hughes Company,” he said. “Hughes has always operated in compliance with Florida’s stringent rules and regulations.”

He said the company’s well-completion process prevents any fluids from contacting underground water by sealing the well off from the reservoir with multiple layers of steel and concrete. “At no time has the groundwater been in any danger of coming into contact with fluids flowing through the well pipe,” he said.

The incident worried nearby residents, who Nelson said found out about the December drilling incident nearly four months after it happened. According to Nelson, the Collier County commissioners are seeking an administrative hearing review with state regulators.

“We cannot tolerate expanded industrial drilling activities that pose a threat to the drinking and surface water so close to the Florida Everglades,” Nelson said in his letter to EPA Administrator Gina McCarthy. “The recent discovery of a fracking-like incident there raises serious concerns about whether outside wildcatters would soil one of the world’s great environmental treasures.”

He added that neighbors and families are rightly concerned about having so-called “produced water” from oil and gas wells injected beneath their freshwater aquifer. He is asking the EPA to lend its expertise to the state of Florida and review the groundwater data submitted by Hughes or the Department of Environmental Protection.